Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA.
Proc Biol Sci. 2023 Sep 27;290(2007):20231636. doi: 10.1098/rspb.2023.1636.
Periodic fluctuations in abiotic conditions are ubiquitous across a range of temporal scales and regulate the structure and function of ecosystems through dynamic biotic responses that are adapted to these external forces. Research has suggested that certain environmental signatures may play a crucial role in the maintenance of biodiversity and the stability of food webs, while others argue that coupled oscillators ought to promote chaos. As such, numerous uncertainties remain regarding the intersection of temporal environmental patterns and biological responses, and we lack a general understanding of the implications for food web stability. Alarmingly, global change is altering the nature of both environmental rhythms and biological rates. Here, we develop a general theory for how continuous periodic variation in productivity, across temporal scales, influences the stability of consumer-resource interactions: a fundamental building block of food webs. Our results suggest that consumer-resource dynamics under environmental forcing are highly complex and depend on asymmetries in both the speed of forcing relative to underlying dynamics and in local stability properties. These asymmetries allow for environmentally driven stabilization under fast forcing, relative to underlying dynamics, as well as extremely complex and unstable dynamics at slower periodicities. Our results also suggest that changes in naturally occurring periodicities from climate change may lead to precipitous shifts in dynamics and stability.
生物因子在不同时间尺度上普遍存在周期性波动，通过适应这些外力的动态生物响应来调节生态系统的结构和功能。研究表明，某些环境特征可能在维持生物多样性和食物网稳定性方面起着至关重要的作用，而另一些人则认为耦合振荡器应该会促进混沌。因此，关于时间环境模式和生物响应的交点仍然存在许多不确定性，我们缺乏对食物网稳定性影响的总体认识。令人担忧的是，全球变化正在改变环境节律和生物速率的性质。在这里，我们发展了一个一般理论，说明跨时间尺度的生产力连续周期性变化如何影响消费者-资源相互作用的稳定性：这是食物网的基本组成部分。我们的结果表明，在环境胁迫下的消费者-资源动态具有高度复杂性，并且取决于相对于基础动态的胁迫速度以及局部稳定性特性的不对称性。这些不对称性允许在相对于基础动态的快速胁迫下实现环境驱动的稳定化，以及在较慢的周期性下极其复杂和不稳定的动态。我们的结果还表明，气候变化引起的自然周期性变化可能导致动态和稳定性的急剧变化。
